Doctor Who: The Krotons

When the Tardis arrives on the planet of the Gonds, the Doctor, Jamie, and Zoe discover a world ruled and enslaved by the Krotons. The brightest Gonds are always chosen to serve as companions of the Krotons and are never seen again. The Doctor and his friends decide to put a stop to the their rule, but in doing so, inadvertently unleash the true power and terror of the Krotons.